Electrical Interface
The system has 1 external connector:
1.Power supply and communication interface X1.
2.1 cable is connected to X1 at one end, the other end is divided all the way to power the red and black clips as well as divided into 3 serial ports, respectively COM1~COM3, where COM1 is RS422, COM2 and COM3 are RS232. COM1 can be used to send working mode commands;
3.The external connector points are defined as shown in Table 1:
Table 1. X1 connector point definition
Instructions for use
1、System Workflow
The inertial guidance system consists of two workflows, a combined navigation process and a pure inertial navigation process.
1.1、Start-up prompt message
Connect the cable, power up the system, monitor the COM1 interface information through the serial debugging tool of the test computer, and send workflow commands to the COM1 interface through the serial debugging tool after the interface displays "Please enter NaviMode within 20s! "If the command is not sent within 20s, the system will automatically enter the internal saved workflow after 20s.
1.2、Portfolio navigation process
After entering the combined navigation process, the first binding satellite information, if the satellite does not position, it is in the state of waiting for satellite information; when the satellite information is valid, it enters the alignment state, alignment time 1min, alignment period requires the inertial guide stationary, alignment is complete, the inertial guide can move, the system is in the combined navigation state.
1.3、Pure inertial navigation process
After entering the pure inertial navigation process, the first 1min coarse alignment, if the satellite information is valid, the binding satellite information for 1500s fine alignment, if there is no satellite information, the static base must be aligned 1500s; alignment is completed after the transfer to the pure inertial navigation state, the inertial guidance can move.
2、System configuration commands
2.1、Configuration options and saving
The inertial guidance system provides 3 external serial ports (configuration number: com1, com2, com3), and provides an internal storage channel (configuration number: file), 3 serial ports can be configured, each serial port function assignment and related configuration as follows：
Table 2. Inertial guidance system serial port function assignment table
After the system is powered on and the serial port displays the startup information, you can input commands such as COM1, COM2, COM3 serial port baud rate configuration, serial protocol and update rate setting, etc. If each command output is successful, it will return "cmd ok" or "<OK ", otherwise "cmd error" or "<ERR" will be displayed. After inputting, type "saveconfig" to save this configuration, and the next reboot will automatically call this configuration, if you don't input this command, the configuration of serial port will be restored to the last saved configuration after next reboot.
1.1、Configuration queries
Typing the "log loglist" command through the inertial guide serial port will list all the configurations of COM1, COM2 and COM3, including the following:
1.Serial port number, serial port baud rate, serial port protocol and update rate.
2.Function module open status: including zero speed correction status and smooth processing status, open as enable, close as disable; carrier type;
3.Internal storage status information: including the file name of the last file, remaining space, etc;
4.Initial binding latitude and longitude;
5.System number and production date;
6.Software version number: including preprocessing software version number and navigation software version number;
7.Operating modes: including combined navigation (DGI) and pure inertial navigation (INS).
1.2、Baud rate configuration
1.Enter the following command in this mode to enter the serial port baud rate configuration:
com comX BAUDRATA
2.Where X is 1~3 and BAUDRATA is the baud rate in bps.
For example, to set the baud rate of COM2 port to 460800bps, enter the following command:
com com2 460800
1.3、Update Rate Configuration
The configuration of COM1~COM3 and memory file port SNCNAVPVTA/B, BDFPD, INSPVASA/B and other protocols through the inertial guide serial port is performed with the following configuration commands:
log comX/file LOG ontime updataTime
where comX can be com1~com3 configuration number, file for the memory interface configuration number; updataTime represents the update time, can be 5 (0.2Hz), 1 (1Hz), 0.2 (5Hz), 0.1 (10Hz), 0.01 (20Hz) and other periods that can be 200Hz frequency division, unit s.
LOG indicates the protocol name, can be inspvasa, inspvasb, bdfpd, etc.
For example, to configure the COM2 port to output 10Hz SNCNAVPVTA data, the following command can be entered through the inertial guide serial port:
log com2 sncnavpvta ontime 0.1
If you need to output 10Hz bdfpd data at COM2 at the same time, you can then enter the following command through the inertial guide serial port:
log com2 bdfpd ontime 0.1
As a further example, to store 1 Hz of the inspvasa protocol data into the internal memory of the inertial guide, the following command can be entered through the serial port of the inertial guide:
log file inspvasa ontime 1
If you want to turn off a protocol, the configuration command is as follows:
log comX/file LOG off
The configuration of the rawimusb protocol for COM1~COM3 ports and memory file port is performed through the inertial guide serial port with the following configuration commands:
log comX/file rawimusb onchanged
If you want to turn off the rawimusb protocol for this serial port, the configuration command is as follows：
log comX/file rawimusb off
If you want to disable all protocols on the serial port, the following command is configured：
unlogall comX/file
Note that increasing the update rate or outputting several protocols at the same time, these will increase the amount of data sent by the serial port, and you need to configure the baud rate to match it before using it, otherwise it may cause lost numbers. In general, the larger the amount of data, the higher the baud rate required.
1.4、Initial value latitude and longitude configuration
Initial latitude and longitude configuration, the configuration command is：
initialpos LONGITUDE LATILUDE
where LONGITUDE and LATITUDE are the configured local latitude and longitude values, in degrees.
1.5、Function module configuration
The function modules with on configuration mainly include zero speed correction and output position smoothing.
1.5.1、"Zero speed correction" configuration
Zero speed correction function mainly refers to the inertial guide to detect the sensitive information, if the inertial guide is judged to be zero speed, then make the corresponding correction.
If the satellite information is invalid for a long time in the combined navigation state, and the user wants to get pure inertial navigation information, it is recommended to turn off the zero speed correction mode.
Zero speed correction configuration commands are as follows:
inszupt switch
The switch value is disable or enable, where disable means turn off the function and enable means turn on the function.
2.6.2 、"Position output smoothing" configuration
The position information in protocols such as INSPVASA and BDFPD is inertial guidance navigation position information. To get smoother position information, a position output smoothing function is added to the navigation software, and the smoothed position noise is smaller.
This product in the combination of navigation process "position output smoothing" default is off, in order to facilitate the user to choose, this function can be configured, configuration instructions are as follows:
possmooth SWITCH
The switch value is disable, enable, where disable means turn off the function, enable means turn on the function.
2.7 Carrier type configuration
According to the different carriers installed in the inertial guidance, the carrier type configuration is required, and for different carrier types, different algorithms are processed within the system.
The configuration commands are as follows:
carrier vehicle/ship/air
In order, they are vehicle, ship and airborne.
After the configuration is complete, you need to enter the save command saveconfig and then hard boot or enter the #reset command, the carrier type configuration will be valid after the boot. The inertial guide does not support the current configuration for current use during use, it must be restarted.
After the carrier type is configured as vehicle type, the inertial guide is required to be installed on the vehicle and fixed, and the inertial guide is oriented in the same direction as the front of the carrier vehicle, with an error of not more than 10 degrees.
2.8 、GNSS antenna pole arm configuration
Depending on the relative mounting relationship between the antenna and the inertial guide, an antenna rod arm configuration is required. The value of the rod arm between the configured inertial guide to the antenna must be measured to the nearest millimeter (mm), any rod arm measurement error will go directly into the position error of the inertial guide output, when installed and used, the inertial guide is as close as possible to the main antenna, especially in the horizontal position. This command is required before the inertial guide is aligned with the static base or in the middle and before the dynamic base is aligned. Once this configuration is complete, it needs to be saved via "saveconfig".
The configuration includes master antenna pole arm configuration and slave antenna pole arm configuration.
The master antenna configuration command is as follows:
setimutoantoffset1 armX army armZ
The slave antenna configuration command is as follows：
setimutoantoffset2 armX army armZ
Where armX, armY and armZ are the configured rod arm values in meters, representing the component of the vector from the inertial guide to the antenna phase center within the inertial guide vector coordinate system, which is chosen to be right front up (XYZ). For the example in Figure 4, armX and armY should have negative values and armZ should have positive values.
Figure 4 Schematic diagram of antenna pole arm
2.9、 Output lever arm setting
The default value for the product output lever arm configuration is [0, 0, 0] (upper right front), which is the position and velocity value at the output inertial guide. If you need to output the position and velocity of the user's test point, you need to set the output lever arm according to the relative mounting relationship between the test point and the inertial guide.
The bar arm value between the configured inertial guide and the test point must be measured to the nearest millimeter (mm) and any bar arm measurement error will go directly into the position error of the inertial guide output. This command is required before the inertial guide's static base is aligned or before the inertial guide's dynamic base is aligned. Once this configuration is complete, it needs to be saved via "saveconfig".
The output lever arm configuration command is as follows:
setimutosensoroffset armX armY armZ
where armX, armY and armZ are the configured rod arm values in meters, representing the component of the vector from the inertial guide to the test point in the inertial guide vector coordinate system, which is selected as right front up (XYZ). Figure 5 example, armY, armZ should be positive values.
Figure 5 Schematic diagram of output lever arm
2.10、 Mounting angle setting
Both the attitude and heading information output by the product are the Euler angles of the product coordinate system with respect to the geographic coordinate system. The angular mounting relationship between the product and the carrier coordinate system is the mounting angle, and the configuration default value is [0, 0, 0] (pitch, heading, roll), which means that the product coordinate system is considered to overlap with the mounting carrier coordinate system. If there is a mounting angle for the product installed on the carrier, and the product is required to output the Euler angle of the carrier coordinate system relative to the geographic coordinate system, the mounting angle should be set according to the relative mounting relationship between the product and the carrier.
The installation angle configuration command is as follows:
vehiclebodyrotation angleX angleZ angleY
where angleX, angleZ, and angleY are configured mounting angle angle values in degrees, representing the angle from the carrier coordinate system to the combined navigation system coordinate system in the order of pitch, heading, and roll.
Note: This function will cause the output angular velocity, acceleration, and attitude to change with the settings.
1、Protocol format
The output protocols supported by the product are shown in the following table.
Table 3. Description of output data protocols
3.1 、SNCNAVPVTB
Example of inertial configuration commands:
log com2 sncnavpvtb ontime 1
Table 4. sncnavpvtb format
3.2、 SNCNAVPVTA
Example of inertial guidance configuration commands:
log com2 sncnavpvta ontime 1
Table 5. SNCNAVPVTA format
3.3 BDFPD
Example of inertial configuration command:
log com2 bdfpd ontime 1
Inertial guidance output example
$BDFPD,2105,355160.246,90.96184,-1.14427,1.01899,39.71066564,116.11209956,46.076,-0.0037,-0.0065,0.0147,20,16,0*68
Table 6: BDFPD format
3.4 Short Message Protocol Header
There are two types of short header protocol headers, one is ASCII and the other is binary.
Table 7. ASCII short header
3.5 、32-bit CRC checksum
The C code history is as follows
#define CRC32_POLYNOMIAL 0xEDB88320L
/* --------------------------------------------------------------------------
Calculate a CRC value to be used by CRC calculation functions.
-------------------------------------------------------------------------- */
unsigned long CRC32Value(int i)
{
int j;
unsigned long ulCRC;
ulCRC= i;
for ( j = 8 ; j >0; j-- )
{
if ( ulCRC&1 )
ulCRC= ( ulCRC>>1 ) ^ CRC32_POLYNOMIAL;
else
ulCRC>>= 1;
}
return ulCRC;
}
/* --------------------------------------------------------------------------
Calculates the CRC-32 of a block of data all at once
ulCount - Number of bytes in the data block
ucBuffer - Data block
-------------------------------------------------------------------------- */
unsigned long CalculateBlockCRC32( unsigned long ulCount, unsigned char*ucBuffer)
{
unsigned long ulTemp1;
unsigned long ulTemp2;
unsigned long ulCRC= 0;
while ( ulCount-- != 0 )
{
ulTemp1 = ( ulCRC>>8 ) &0x00FFFFFFL;
ulTemp2 = CRC32Value( ((int) ulCRC^ *ucBuffer++ ) &0xFF );
ulCRC= ulTemp1 ^ ulTemp2;
}
return( ulCRC );
}
3.6、 INSPVAS
The command is short message protocol output
Inertial guidance configuration command example:
log com2 inspvasa ontime 1
ASCII example
$INS,091202,083559.00,A,4717.11437,N,00833.91522,E,499.6,M,0.004,77.52,0.02,0.00,0.00,327.19,001.69,000.00,0.00,0.00,0.00,E*64
Table 9: INSPVAS format
3.7、 RAWIMUS
The command is short message protocol output (output binary only)
Example of inertial configuration command:
log com2 rawimusb onchanged (binary)
Table 10: RAWIMUS format
1、Data logging
This product has data storage function, total storage space 16G (internal will contain system recovery partition and other files used by the system, so it will be less than the normal empty SD card). The system automatically saves the storage information according to the user's configuration. The saved data folder is named recordX, where X is the file number (the maximum is 39), and the number increases sequentially. When X is 39, the next storage will automatically overwrite record00, and X will still increase sequentially in the next storage. If the system is configured to store data state, the system will automatically delete the earliest data folder after each power-on operation, for example, if the current generated file is record08, there will be no record09 folder in the system memory. Users can use this as a basis to find the latest data file. In addition, the current latest file name is also displayed when a configuration query is made.
The recordX folder contains the protocol files configured by the user, each protocol is a separate file with the protocol name.
CAUTIONS
1.Inertial guidance system power on and off time interval of not less than 30s, otherwise it is easy to cause damage to inertial devices;
2.In the handling, installation and use of the process, should be light, avoid bumping, dropping and impact;;
3.After the inertial guide is turned on, you need to wait for the inertial guide to complete coarse alignment before linear motion, coarse alignment time of about 1min, or affect the measurement accuracy;
4.Carrier type configuration for the vehicle type, the inertial guide is required to be installed in the car fixed, and the inertial guide direction and the direction of the front of the carrier car, the error is not more than 10 degrees.
40μJ High refrequency erbium glass laser.High refrequency erbium glass laser.
Type 98 Rotary Fiber Strapdown Inertial Navigation System.Fiber Strapdown INS surveying
RLG Single-Axis Indexing Inertial Navigation System.Navigation and Guidance Systems
RLG Two-Axis Indexing Inertial Navigation System.Precision Navigation Technology
